September 17, 2007

Via EDGAR

Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Ladies and Gentlemen:

Quantum Corporation (the “Company” or “Quantum”) submits this letter in response to the comment from the Staff of the Securities and Exchange Commission (the “Staff”) received by letter dated August 31, 2007 relating to the Company’s Form 10-K for the fiscal year ended March 31, 2006, filed June 12, 2006.

In this letter, we have recited the comment from the Staff in italicized, bold type and have followed it with the Company’s response.

Form 10-K for the Year Ended March 31, 2006

Consolidated Financial Statements

Consolidated Statements of Operations, page 50

Response:

In preparing our response to prior comment 3, we considered both quantitative and qualitative aspects of reclassifying the STK litigation settlement expense. From a quantitative perspective, reclassification of the STK litigation settlement from a separate line below loss from operations to a separate line as a component of operating expenses would not be material in that it would have resulted in no change in revenue, cost of

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revenue, gross margin, trended operating expenses, net loss before income taxes, net loss or earnings per share for fiscal year and fourth quarter 2006, respectively. In addition, there would be no impact to our balance sheet, statement of stockholders’ equity or statement of cash flows related to the reclassification for those same periods.

Operating expenses would have increased 8% and 30% for fiscal year and fourth quarter 2006, respectively. This reclassification would have increased operating expense as a percentage of revenue by 3% and 9% for the same periods, respectively. However, as our proposed reclassification of the litigation settlement would be presented as a separate line included within operating expenses, there would be no change in research and development, sales and marketing and general and administrative expenses for either period.

Since our operating losses were relatively small, any change to operating expenses (e.g., reclassification of the STK litigation settlement expenses to operating expenses) would mathematically have a relatively larger impact on operating loss on a percentage basis. For example, the fiscal year 2006 operating loss would have been nearly double and fourth quarter 2006 operating loss would have more than tripled as a result of reclassifying the STK litigation settlement. However, we don’t believe those changes would be considered significant to our shareholders, analysts or management as their focus regarding their evaluation of our financial performance is on recurring revenue, recurring operating expenses and our ability to generate cash. The litigation settlement did not have an impact on our recurring trended revenue and expenses or future ability to generate cash.

Furthermore, we considered the qualitative materiality factors in SAB 99 and have determined that, based on those factors, the reclassification of the settlement is not material. Some of the more significant considerations are highlighted below:

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Management considered all these quantitative and qualitative factors discussed above in concluding that the reclassification is not material to our financial statements.

We hope that you will find the foregoing responsive to the Staff’s comments. If you have any further questions or comments, please direct these to me at (425) 895-3187. In addition, we would request that you provide a facsimile of any additional comments that you may have to my attention at (425) 895-3370. Thank you for your assistance.

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